Occupant Safety Device For Roof Reinforcement

ABSTRACT

An occupant safety device for a motor vehicle having a roof. The safety occupant device comprises a support structure slidably mounted within the vehicle that, upon actuation, extends vertically upwardly within the vehicle to cooperate with the vehicle&#39;s roof to increase the amount of weight that the roof can support. The support structure includes an overhanging top portion having a length and a direction of overhang that, upon actuation of the support structure, provide early roof engagement in the event of roof crush.

BACKGROUND OF THE INVENTION

1. Field of Invention

This invention relates to the field of reinforcing vehicles to lessenroof crush during rollover. More specifically, this invention relates toa reinforcement that can be deployed during a vehicle rollover tocooperate with the vehicle roof to lessen roof crush during therollover.

2. Background

United States Federal Motor Vehicle Safety Standard (FMVSS) 216 is arequirement designed to protect vehicle occupants in the event of arollover accident. New standards require that, by 2009, roof deformationbe limited to five inches (127 mm) of crush. Under the new standard, avehicle's roof structure will have to support 2.5 times the vehicleweight or 5,000 pounds, whichever is less (up from the previousrequirement of 1.5 times the vehicle weight).

Presently, most non-convertible automobiles have pillared hardtops. Apillared hardtop typically includes a framework of A-pillars, B-pillars,C-pillars, and interconnecting roof rails and headers. This frameworkprotects vehicle occupants should a rollover condition occur, bylimiting roof crush. The A-pillars are typically located on the sides ofthe vehicle's front windshield. The C-pillars are typically located onthe sides of the vehicle's rear window. The B-pillars are typicallylocated about midway between the A-pillars and the C-pillars. The roofrails and headers extend between the pillars longitudinally andtransversely.

To strengthen roof structures to meet the new requirements, there are anumber of alternatives that are commonly used. The most common practiceto strengthen the roof structure is to increase the strength of theA-pillar, B-pillar, and C-pillar, as well as the roof rails and headers.Strengthening these elements is most commonly achieved by increasingtheir size and thickness, which can increase vehicle weight andproduction costs. Other ways to strengthen these elements include usingstronger materials, which may be prohibitively expensive to obtain oruse in existing production facilities, and adding additional supportelements, which also increases vehicle weight and production costs.

It has been proposed, in convertible vehicles that do not haveprotective roof structures, to employ rollover bars that are enclosedwithin or otherwise attached to a vehicle's seat. The rollover bars areactivated, upon sensing a rollover condition, to extend upward toprotect the seat occupant during rollover. These rollover bars aredisclosed to be desirable due to the lack of a protective roof structurein convertible vehicles, and are not adapted or designed to work incooperation with a pillared hard top to reinforce the pillared hard top.

BRIEF SUMMARY OF THE INVENTION

In one embodiment, the invention is directed to an occupant safetydevice for a motor vehicle having a roof. The safety occupant devicecomprises a support structure slidably mounted within the vehicle that,upon actuation, extends vertically upwardly within the vehicle tocooperate with the vehicle's roof to increase the amount of weight thatthe roof can support. The support structure includes an overhanging topportion having a length and a direction of overhang that, upon actuationof the support structure, provide early roof engagement in the event ofroof crush or in the event of a vehicle rollover.

In another embodiment, the invention is directed to a method of makingan occupant safety device for a motor vehicle having a roof. The methodcomprises providing a support structure having an overhanging topportion and slidably mounting the support structure within the vehicleso that, upon actuation, the support structure extends verticallyupwardly within the vehicle to cooperate with the vehicle's roof toincrease the amount of weight that the roof can support. The overhangingtop portion has a length and direction of overhang that provide earlyroof engagement upon actuation in the event of roof crush.

Further features of the present invention, as well as the structure ofvarious embodiments of the present invention are described in detailbelow with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated herein and form partof the specification, illustrate the present invention and together withthe description, further serve to explain the principles of theinvention and to enable a person skilled in the pertinent art to makeand use the invention. In the drawings, like reference numbers indicateidentical or functionally similar elements.

FIG. 1 illustrates a prior art vehicle seat having a headrest.

FIG. 2 illustrates a vehicle seat including a reinforcement inaccordance with the present invention.

FIG. 3A is a front view of a reinforcement in accordance with thepresent invention.

FIG. 3B is a side view of the reinforcement shown in FIG. 3A, takenalong line 3A-3A.

FIGS. 4A-4C are alternate cross-sectional views of a portion of areinforcement in accordance with the present invention.

FIG. 5 illustrates an embodiment of an activation mechanism for areinforcement in accordance with the present invention.

FIG. 6 illustrates an embodiment of a reinforcement in accordance withthe present invention, being utilized in a vehicle during a rolloversimulation test.

FIG. 7 illustrates exemplary forces acting on a reinforcement during arollover simulation test.

FIG. 8A is a front view of an embodiment of a reinforcement of thepresent invention, with an overhanging top portion.

FIG. 8B is a side view of the reinforcement of FIG. 8A.

FIG. 8C is a perspective view of the reinforcement of FIG. 8A.

FIG. 9 illustrates exemplary forces acting on a reinforcement of thepresent invention during vehicle rollover, and also illustratesexemplary deformation of a vehicle floor and roof during rollover.

DETAILED DESCRIPTION OF THE INVENTION

The present invention provides a roof reinforcement or supportstructure. An occupant safety device for an automotive vehicle lessensroof crush during vehicle rollover and comprises the roof reinforcementor support structure. The reinforcement is preferably deployed during avehicle rollover to cooperate with the vehicle roof to limit roof crush.

FIG. 1 illustrates a prior art vehicle seat 10 including a seat backportion 20 and a headrest 30. It is known to mount headrests 30 on theseat back portion 20 via vertical supports 40. It is most common toemploy two vertical supports 40 for each headrest 30, and to fashion thesupports 40 so that the headrest 30 is vertically adjustable to alimited extent for occupant comfort. It is also known to reinforcevehicle seats in a number of ways to increase occupant safety in theevent of side and rear impact collisions.

FIG. 2 illustrates a vehicle seat including an embodiment of areinforcement in accordance with the present invention. Vehicle seat 100is situated in a vehicle having a roof portion 200. The seat 100includes a bottom portion 110 and a back portion 120. The seat 100 alsopreferably includes a headrest 130. Mounted within the seat 100 is areinforcement 300 (see FIG. 3A) having at least one vertical portion 310and a horizontal portion 320. The reinforcement is preferably mountedwithin the seat back 120 so that its at least one vertical portion 310can slide substantially vertically within the seat back 120 as shown inFIG. 2.

As schematically illustrated in FIG. 2, a sensor 210 is connected to thereinforcement, preferably via an electrical line 220. The sensor 210 iscapable of sensing a condition for which roof reinforcement isdesirable. Upon sensing such a condition, the sensor 210 sends a signalto the reinforcement 300 via the electrical line 220 to suitably deploythe reinforcement so that it reinforces the vehicle roof.

As shown in FIG. 2, the seat's headrest 130 preferably covers thehorizontal portion 320 of the reinforcement 300. During normal operationof the vehicle, the reinforcement 300 is mounted within the seat backportion 120 in a lowered position (not shown) such that the headrest 130is properly positioned for occupant comfort and safety during normaldriving conditions. In a particularly preferred embodiment of theinvention, the reinforcement 300 is mounted within the seat back portion120 so that the headrest height is adjustable to a limited extent forthe vehicle occupant. However, if the sensor 210 senses a condition forwhich roof reinforcement is desirable, the reinforcement 300 can beactivated/deployed by an activation mechanism (discussed below) toextend upwardly within the seat back 120 so that it is properlypositioned to reinforce the vehicle roof 200.

By way of example, a reinforcement 300 in accordance with the presentinvention may extend upwardly from four to six inches upon deployment.This distance varies by vehicle, and can depend on the distance betweenthe top of the seat back portion 120 and the vehicle roof 200.

FIG. 3A is a front view of a reinforcement in accordance with thepresent invention. As shown, horizontal portion 320 extends between twovertical portions 310. Although the illustrated embodiment includes twovertical portions 310, the present invention contemplates one or morevertical portions. The horizontal portion 320 preferably extends acrossthe top of the vertical portions 310, and spans the width of thevertical portions 310. In the embodiment illustrated in FIG. 3A, acrossbar 360 extends between the vertical portions 310 to increase thestructural stability of the reinforcement 300.

The vertical portions 310 preferably are slidably seated in hollowpillars 330 so that they can slide vertically within the pillars 330 apredetermined amount. The pillars 330 are preferably fixedly mounted tothe vehicle seat 100. In a preferred embodiment of the invention, anactivation mechanism 340 is housed within the pillars 330 and is indirect or indirect contact with the vertical portions 310. Theactivation mechanism 340 is activated to drive the vertical portions 310to an extended position substantially upward relative to the seat 100.Although the activation mechanism 340 shown in FIG. 3A is a coil spring,any known, suitable activation mechanism can be employed, includingother spring systems and pyrotechnic devices (not shown).

Although FIG. 3A discloses an activation mechanism 340 for each of thetwo vertical portions 310 of the reinforcement 300, the presentinvention also contemplates a single activation mechanism for thereinforcement 300, even if there is more than one vertical portion, orother suitable combinations of numbers of activation mechanisms andvertical portions.

FIG. 3B illustrates a side view of the reinforcement shown in FIG. 3A,taken along line 3B-3B. In this embodiment, the activation mechanism 340is shown to be in direct contact with a bottom surface 350 of thevertical portion 310 that it activates.

The reinforcement 300 preferably comprises a retaining mechanism thatretains the support structure in its extended/deployed position. Theretaining mechanism is shown to include a cutout portion 370 of thepillar 300, into which, for example, a spring-loaded or otherwise biasedprotrusion (not shown) passes through the cutout portion 370.

In a preferred embodiment of the invention, a cushion is provided toprotect the occupant's head when the headrest 130 has been extended toan activated position. The cushion may include, as illustrated in FIG.2, a portion 140 of the seat 100 that extends from the seat back 120 toprotect the occupant's head. Additionally or alternatively, the presentinvention contemplates a soft coating for the vertical portions 310 toprotect the occupant's head, or an air bag that can be deployed with thereinforcement 300 to replace the headrest 130 upon deployment.

FIGS. 4A through 4C illustrate contemplated cross sections of the atleast one vertical portion 310 of the reinforcement 300. While threepossible shapes are illustrated, the present invention contemplates avariety of suitable shapes and sizes for the vertical portion's crosssection. FIG. 4A illustrates a modified C-shaped cross section having anouter wall 410, two side walls 420 and two additional walls 430 thatincrease the structural strength of the vertical portion. In oneexemplary embodiment, the cross-sectional dimensions of the verticalportion are 15 mm×50 mm, with the walls having a thickness of about 2mm.

FIG. 4B illustrates another exemplary embodiment of a cross section ofthe vertical portions. This C-shaped cross section includes the outerwall 410 and side walls 420 of the modified C-shaped cross section, butdoes not include the additional walls 430. In use, the outer wall 410 ispreferably located at an outermost side location S (see FIG. 3A) of thereinforcement 300. This arrangement of the outer wall 410 increases thestructural strength of the reinforcement for the forces characteristicof vehicle rollover. FIG. 4C illustrates a known I-shaped cross section.

In a preferred embodiment, the reinforcement 300 comprises ultra highstrength steel (UHSS). In a particularly preferred embodiment, thereinforcement 300 comprises boron. The present invention contemplatesdifferent components of the reinforcement 300 being made from differentsuitable materials. The materials should be suitably light and strong,and also should be economically feasible to use.

FIG. 5 illustrates an embodiment of an activation mechanism for areinforcement in accordance with the present invention. Sensor 210 iscapable of sensing a crash condition for which vehicle roofreinforcement is desirable, such as a vehicle rollover. Sensor 210 ispreferably connected to the activation mechanism 340 for thereinforcement 300 via an electrical line 220. As shown in FIG. 5, whenthe activation mechanism 340 is a pre-loaded spring or other preloadedspring system, a pre-tension device 500 may be provided between thesensor 210 and the activation mechanism 340. The pre-tensioner 500 pullsa cable 510 that slides a plate 520 extending into the pillar 330 torelease the spring to activate the vertical portion 310 residing in thepillar.

Upon sensing a crash condition for which vehicle roof reinforcement isdesirable, the sensor 210 sends a signal to the reinforcement 300 viathe electrical line 220 to activate the activation mechanism 340 andsuitably deploy the reinforcement 300 so that it reinforces the vehicleroof 200. As stated above, although the activation mechanism 340 isdepicted as a coil spring, any known, suitable activation mechanism canbe employed, including other spring systems and pyrotechnic devices.

FIG. 6 schematically illustrates a reinforcement in accordance with thepresent invention, being utilized in a vehicle during a rolloversimulation test. The reinforcement 300 is shown extending from a seat100 of a vehicle. The embodiment of the reinforcement 300 illustrated inFIG. 6 includes two crossbars 360 a and 360 b. In the embodiment of thereinforcement shown, when employed during a rollover condition orsimulated rollover condition, crossbar 360 a is in compression andcrossbar 360 b is in tension.

The simulated rollover condition is created when a simulator plate 700impacts the vehicle with a given force. The force can be, for example,based on the calculated forces exerted during a rollover, or based on aset weight such as a multiple of the vehicle's weight. As stated above,FMVSS 216 requires that, by 2009, a vehicle's roof structure will haveto support 2.5 times the vehicle weight or 5,000 pounds, whichever isless. The simulator plate 700 commonly impacts the vehicle at thejunction of the sides 610 and roof 200 of the vehicle, in the area ofboth the A pillar (not shown) and the roof rail 620 of the vehicle.

As can be seen in FIG. 6, the activated reinforcement 300 extends towardthe roof of the vehicle and may stop just short of the roof or uponcontacting the roof. Extension is stopped when the protrusion of theretaining mechanism passes through the cutout portion 370 and retainsthe reinforcement in its extended portion as discussed above. Uponactual or simulated rollover impact, roof crush is limited when the roofcontacts the reinforcement 300 because the reinforcement providessupport that limits further crush.

The reinforcement 300 is preferably mounted to the vehicle seat 100.Although vehicle seats are commonly reinforced to a limited extent in anumber of ways to increase occupant safety in the event of side or rearimpact collisions, the seat 100 supporting the reinforcement 300 mayinclude additional framing to allow the seat 100 to provide a suitablesupport for the reinforcement 300. The seat 100 is commonly mounted tothe vehicle floor 600. The present invention contemplates reinforcingthe vehicle floor 600 so that it provides a suitable support for theseat 100 and the reinforcement 300.

With respect to the forces commonly generated during vehicle rollover,components of the vehicle that provide occupant protection during arollover condition, such as the A-pillars, B-pillars, C-pillars, rails,and headers, are subject to bending forces during rollover due to theirposition relative to the forces generated during rollover. The bendingforces that are generated during vehicle rollover cause deformation ofthese components, making them much less effective than a componentpositioned so that rollover forces act upon it axially. Similarly,forces applied to the vertical portions 310 of the reinforcement 300during a vehicle rollover have both an axial component and a bendingcomponent. As a general principal, bending forces cause greaterdeformation of the vertical portion than do axial forces, so that thereinforcement 300, like other structural supports, is more effectiveagainst applied axial forces.

FIG. 7 illustrates exemplary forces acting on a reinforcement 300 beingutilized in a vehicle during a rollover simulation test. As can be seen,the simulator plate 700 presses on the vehicle, exerting a roof crushforce F₁ on the vehicle roof 200. The direction of the counter force F₂exerted by an activated reinforcement 300 can, in part, depend on theposition of the seat back 120 and is exerted at an angle α to thedirection of the roof crush force F₁. Ideally, the reinforcement 300would be positioned such that the counter force F₂ exerted by anactivated reinforcement 300 would be directly opposite to the roof crushforce F₁, as represented by force F₃. Such a position for reinforcement300 would cause the rollover forces F₁ to act upon the vertical portions310 of the reinforcement 300 axially, beneficially minimizing oreliminating bending forces applied to the vertical portions 310.

In addition to positioning the reinforcement 300 as a whole such thatthe counter force F₂ exerted by an activated reinforcement 300 would bedirectly opposite to the roof crush force F₁, the present inventioncontemplates the vertical portions 310 being curved (see FIGS. 3B and8B) to minimize the angle α between the counter force F₂ exerted by anactivated reinforcement 300 and the ideal direction F₃ for the counterforce.

FIGS. 8A through 8C illustrate an embodiment of a reinforcement of thepresent invention. In the embodiment of FIGS. 8A through 8C, thereinforcement 300 has an overhanging top portion 320 a. The overhangingtop portion 320 a is similar to the horizontal portion 320 of thepreviously-described embodiments of the reinforcement 300. However, inaddition to extending between vertical portions 310, the overhanging toppotion 320 a also extend past the vertical portions 310 on at least oneside of the reinforcement 300.

The overhanging top portion 320 a preferably has a length and adirection of overhang that, upon actuation of the reinforcement,provides early roof engagement in the event of roof crush. This isbecause, based on the most common characteristics of roof crush, theoverhanging top portion 320 a extends into the crush zone and thus makesearlier contact with the roof during roof crush. This can be seen in theschematic illustration of a vehicle rollover simulation test presentedin FIG. 6.

FIG. 9 illustrates exemplary forces acting on a reinforcement 300 of thepresent invention during vehicle rollover, and also illustratesexemplary deformation of a vehicle floor 600 and roof 200 duringrollover. The reinforcement 300 is mounted directly or indirectly to thevehicle floor 600, and is activated when the sensor 210 (see FIG. 2)senses a crash condition for which vehicle roof reinforcement isdesirable. When activated, the reinforcement 300 extends to contact thevehicle roof 200 to reinforce the roof during rollover.

The reinforcement 300 also cooperates with the vehicle floor 600, viathe seat 100, to provide an amount of floor deformation upon rollover toabsorb collision energy while maintaining an area of occupant headroomas well as a safe passenger space between the roof 200 and the floor600. In FIG. 9, occupant head room is generally illustrated at 810. Thesafe passenger space, which includes the space necessary to preventmajor injuries to an occupant, is generally illustrated at 820.

Floor deformation can increase collision energy absorption during arollover event, which is beneficial because it can lessen the durationof the rollover by absorbing some of the energy that must be dissipatedduring the rollover. In most vehicles, the seat is stronger than thefloor because the seat is designed to protect the occupant from frontand rear impacts, allowing the floor to deform while the seat maintainsits integrity and maintains a safe passenger space 820.

The present invention contemplates the reinforcement 300 being providedat any number of positions within the vehicle. For example, thereinforcement 300 may be provided only for the driver of the vehicle, ormay additionally be provided for the front passenger and even rearpassengers. This method and device for reinforcing a vehicle roof canbeneficially maintain a lower center of gravity in vehicles, and uses aminimal amount of material to provide a desired amount of reinforcement.

1. An occupant safety device for a motor vehicle having a roof, thesafety device comprising: a support structure slidably mounted withinthe vehicle that, upon actuation, extends vertically upwardly within thevehicle to cooperate with the vehicle's roof to increase the amount ofweight that the roof can support, wherein the support structure includesan overhanging top portion having a length and a direction of overhangthat, upon actuation of the support structure, provide early roofengagement in the event of roof crush.
 2. The occupant safety device ofclaim 1, further comprising an activation mechanism to activate thesupport structure.
 3. The occupant safety device of claim 2, wherein theactivation mechanism is connected to a sensor and activates the supportstructure when the sensor senses a crash condition for which vehicleroof reinforcement is desirable.
 4. The occupant safety device of claim1, further comprising a first headrest portion attached to the supportstructure and at least partially surrounding the overhanging topportion, which acts as a headrest when the support structure is notactivated.
 5. The occupant safety device of claim 4, wherein the supportstructure is situated in the vehicle and includes first and secondsubstantially vertical portions, the first substantially verticalportion being located toward an exterior of the vehicle and the secondsubstantially vertical portion being located toward an interior of thevehicle, and wherein the overhanging top portion extends between thefirst and second substantially vertical portions and includes a portionthat overhangs the first substantially vertical portion in a directionof the vehicle exterior.
 6. The occupant safety device of claim 1,further comprising a retaining mechanism adapted to retain the supportstructure in an extended position.
 7. An occupant safety device for amotor vehicle having a pillared roof, the safety device comprising: asupport structure slidably mounted within the vehicle that, uponactuation, extends vertically upwardly within the vehicle to cooperatewith the vehicle's roof to increase the amount of weight that the roofcan support, wherein the support structure includes an overhanging topportion having a length and a direction of overhang that, upon actuationof the support structure, provide early roof engagement in the event ofa vehicle rollover.
 8. The occupant safety device of claim 7, furthercomprising an activation mechanism to activate the support structure. 9.The occupant safety device of claim 8, wherein the activation mechanismis connected to a sensor and activates the support structure when thesensor senses a crash condition for which vehicle roof reinforcement isdesirable.
 10. The occupant safety device of claim 7, further comprisinga first headrest portion attached to the support structure and at leastpartially surrounding the overhanging top portion, which acts as aheadrest when the support structure is not activated.
 11. The occupantsafety device of claim 10, wherein the support structure is situated inthe vehicle and includes first and second substantially verticalportions, the first substantially vertical portion being located towardan exterior of the vehicle and the second substantially vertical portionbeing located toward an interior of the vehicle, and wherein theoverhanging top portion extends between the first and secondsubstantially vertical portions and includes a portion that overhangsthe first substantially vertical portion in a direction of the vehicleexterior.
 12. The occupant safety device of claim 7, further comprisinga retaining mechanism adapted to retain the support structure in anextended position.
 13. A method of making an occupant safety device fora motor vehicle having a roof, the method comprising: providing asupport structure having an overhanging top portion; and slidablymounting the support structure within the vehicle so that, uponactuation, the support structure extends vertically upwardly within thevehicle to cooperate with the vehicle's roof to increase the amount ofweight that the roof can support, wherein the overhanging top portionhas a length and direction of overhang that provide early roofengagement upon actuation in the event of roof crush.
 14. The method ofclaim 13, further comprising providing an activation mechanism toactivate the support structure.
 15. The method of claim 14, wherein theactivation mechanism is connected to a sensor and activates the supportstructure when the sensor senses a crash condition for which vehicleroof reinforcement is desirable.
 16. The method of claim 14, wherein theactivation mechanism comprises at least one spring.
 17. The method ofclaim 14, wherein the activation mechanism comprises a pyrotechnicdevice.
 18. The method of claim 13, further comprising providing a firstheadrest portion attached to the support structure and at leastpartially surrounding the overhanging top portion, which acts as aheadrest when the support structure is not activated.
 19. The method ofclaim 18, wherein the support structure is situated in the vehicle andincludes first and second substantially vertical portions, the firstsubstantially vertical portion being located toward an exterior of thevehicle and the second substantially vertical portion being locatedtoward an interior of the vehicle, and wherein the overhanging topportion extends between the first and second substantially verticalportions and includes a portion that overhangs the first substantiallyvertical portion in a direction of the vehicle exterior.
 20. The methodof claim 13, further comprising providing a retaining mechanism adaptedto retain the support structure in an extended position.